JPH0452080A - Welding gun with transformer - Google Patents

Abstract

PURPOSE:To reduce resistance generated between the transformer and electrodes at a stroke by connecting transformer terminals and the electrodes by electric wires. CONSTITUTION:After a work is transferred to a specified part to be welded, a gun arm 18b is oscillated and the work is held by the electrodes 16b and 16a under operation of a cylinder 24. A high-frequency AC current is supplied between the electrode 16a connected to a terminal 20 of the transformer 14 via an electric wire 22a and the electrode 16b connected to a center tap terminal 21 of this transformer 14 via an electric wire 22b as a welding current. Consequently, the part to be welded of the work is molten and the desired part of this work is joined. As a result, the resistance between the transformer 14 and the electrodes 16a and 16b can be reduced as much as possible and a high current can be obtained efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a welding gun with a transformer configured by connecting a transformer and each electrode of the welding gun with an electric wire.

[Prior Art] Transformer-equipped welding guns are widely used in resistance welding operations. Since this welding gun with a transformer requires a relatively large current, it is desirable to reduce the overall resistance as much as possible.

Therefore, efforts have been made to reduce the resistance and obtain a large current by increasing the contact area of the welding gun, the transformer, and the ounce copper plate that connects them.

[Problems to be Solved by the Invention] However, the above-mentioned conventional technology has a problem in that it is difficult to efficiently obtain a large current because the contact resistance with the ounce copper plate is greater than the resistance of the conductor itself. At that time, it is possible to fix the ounce copper plate to the gun arm of the welding gun by brazing, etc., but in the case of a gun arm that opens and closes, this ounce copper plate is severely damaged and needs to be replaced frequently, so it cannot be fixed. .

Furthermore, when multiple transformers are arranged in parallel, it is necessary to select the shape of the copper plate that connects the terminals of each transformer and the welding gun, taking into consideration the mounting position, etc., which reduces manufacturing work. It becomes complicated.

The present invention solves this type of problem, and provides a welding gun with a transformer that can reduce the resistance from the transformer to the electrode as much as possible and perform efficient resistance welding work. The purpose is to

[Means for Solving the Problems] In order to achieve the above object, the present invention includes: a transformer; a pair of gun arms that can be opened and closed with each other; a holder that attaches an electrode and is detachable from each gun arm; It is characterized by comprising an electric wire for electrically connecting a terminal of the transformer and the electrode.

Further, the present invention includes a plurality of transformers arranged in a predetermined direction, a set of gun arms that can be opened and closed with each other, a holder that attaches electrodes and can be attached to and detached from each gun arm, and terminals of each transformer. and a plurality of electric wires each having the same length for each gun arm and electrically connecting the electric wire to the electrode.

[Function] In the transformer-equipped welding gun according to the present invention described above, since the terminals of the transformer and the electrodes are connected by electric wires, the resistance from the transformer to the electrodes can be reduced at once. Moreover, by using electric wires instead of ounce copper plates, the conductor portions are not damaged when the gun arm is opened and closed.

Furthermore, in the present invention, the plurality of transformers and electrodes are connected by electric wires, and each electric wire has the same length, so that resistance can be reduced and a uniform value of current is supplied from each transformer. That will happen.

[Example] A transformer-equipped welding gun according to the present invention will be described in detail below by giving an example and referring to the attached drawings.

In FIG. 1, reference numeral 10 indicates a welding gun with a transformer according to the first embodiment. This welding gun IO includes a transformer 14 fixed to a gun bracket 12 and an electrode 16.
a, 16b, and a pair of gun arms 18a, 18 that are supported by the gun bracket 12 so as to be able to open and close each other.
b, a terminal 20 led out from the secondary coil (not shown) of the transformer 14, a center tap terminal 21 led out from the middle of this secondary coil, and the electrodes 16a, 1.
6b, each set of electric wires 22a,
22b.

The surfaces of the gun arms 18a and 18b are coated with a resin insulation coating or an insulation coating, and one gun arm 18a is fixed to the gun bracket 12, and the other gun arm 18b is engaged with the cylinder 24.

At the ends of the can arms 18a and 18b, conductor holders 2 are attached.
Electrode 16a via 6a, 26b.

16b is attached. These holders 26a, 26b are connected to gun arms 18a, 18b via nuts 28a, 28b.
removably fixed to.

One end of a set of multiple electric wires 22H is screwed to both sides of the terminal 20 of the transformer 14, and the electric wires 22H
The other end of a is brazed to a copper conductor member 30, and this conductor member 30 is screwed to the holder 26a (see FIG. 2).

The holder 26b side is configured in the same manner as the holder 26a side described above, and the same constituent elements are given the same reference numerals and detailed explanation thereof will be omitted.

The transformer-equipped welding gun according to the first embodiment is constructed as described above, and its operation will be explained next.

First, the parts to be welded of two workpieces (not shown) are overlapped, and after the welding gun 10 is transferred to a predetermined part of the workpieces to be welded, the gun arm 18b is swung under the action of the cylinder 24. The workpiece is then held between the electrodes 16b and 16a. Next, a high frequency alternating current is output under the driving action of an alternating current power source (not shown), and this high frequency alternating current is
An electrode 16a is connected to a terminal 20 of the transformer 14 via an electric wire 22a, and an electrode 1 is connected to a center tap terminal 21 of the transformer 14 via an electric wire 22b.
6b as a welding current. As a result, the part of the workpiece to be welded is melted, and the desired part of the workpiece is joined.

In this case, according to this embodiment, the terminal 20 of the transformer 14
Electric wires 22a, 22b are connected to the center tap terminal 21, and the electric wires 22a, 22b are connected to the electrode 1.
It is fixed to holders 26a and 26b to which 6a and 16b are attached. Therefore, from the transformer 14 to the electrodes 16a, 16b
The effect is that the resistance between the two ends can be made as small as possible, and a large current can be obtained efficiently.

Furthermore, by using the flexible electric wires 22a and 22b, the electric wires 22a and 22b can be used, especially when the gun arm 18b swings.
This method has the advantage that it does not cause damage to the substrate, and has improved durability compared to conventional multilayer ounce copper plates.

Furthermore, a set of electric wires 22a and 22b are screwed to both sides of the terminal 20 and center tap terminal 210, respectively.

Therefore, uniform current is supplied to the electric wires 22a and 22b,
A large current of a desired value can be supplied to the electrodes 16a, 16b with high precision, and the diameters of the electric wires 22a, 22b are reduced, making them even more difficult to break.

In the first embodiment, the conductor member 30 to which the electric wires 22a and 22b are brazed is configured to be detachable from the holders 26a and 26b. It can also be fixed.

Next, a welding gun with a transformer according to a second embodiment of the present invention will be described below with reference to FIGS. 3 and 4. Note that the same reference numerals are given to the same components as those of the welding gun 10 according to the first embodiment, and detailed explanation thereof will be omitted.

In this case, the welding gun 50 according to the second embodiment has four transformers 14a to 1 arranged in a predetermined direction.
4d, and each terminal 2 of the transformers 14a to 14d
0a to 20d and one conductor member 30a, and each center tap terminal 21a to 21d and the other conductor member 30
A is connected to each gun arm 18a, 18b via four electrical wires 52a, 52b each having the same length and coated with insulation. This electric wire 52
a and 52b are held on gun arms 18a and 18b by holding members 54a and 54b, respectively.

The conductor member 30a is fixed to the holders 26a and 26b by screwing or brazing.

The welding gun 50 configured in this manner has the same effects as the welding gun 10 according to the first embodiment, and in particular, since each electric wire 5.2a, 52b has the same length, each transformer 14a to There is an effect that a uniform value of current is efficiently supplied from the electrode 14d to the electrodes 16a and 16b.

[Effects of the Invention] As described above, the transformer-equipped welding gun according to the present invention has the following advantages:
It has the following effects or advantages.

Since the terminals of the transformer and the electrodes are connected by electric wires, the resistance generated between the transformer and the electrodes can be reduced at once. Moreover, when the gun arm opens and closes, it is possible to reduce damage to the electric wires at once compared to the case where conventional ounce copper plates are used.

Furthermore, in the present invention, since the plurality of transformers and the electrodes are connected by the plurality of electric wires having the same length,
In addition to reducing resistance, each transformer can efficiently supply a large current with a uniform value.

2 is a partially exploded perspective view of the welding gun, FIG. 3 is a schematic front view of a welding gun with a transformer according to a second embodiment of the present invention, and FIG. 4 is a cross section taken along the line IV-IV in FIG. 3. It is a diagram.

10... Welding gun 12... Gun bracket 14.14 a to 14 d-) Lances 16a, 16
b...Electrodes 18a, 18b--Gun arm 20.20a~20 d-...Terminal 21.21a~
21d... Center tap terminals 22a, 22b...
Electric wire 24...Cylinder 26a, 26b...Holder 50...Welding gun 52a, 52b-...Electric wire

[Brief explanation of the drawing]

FIG. 1 is a schematic front view of a welding gun with a transformer according to a first embodiment of the present invention;

Claims (3)

[Claims] (1) A transformer, a pair of gun arms that can be opened and closed with each other, a holder that attaches an electrode to each gun arm and can be detached from the other, and an electric wire for electrically connecting the terminals of the transformer and the electrodes. A welding gun with a transformer. (2) A welding gun with a transformer according to claim 1, wherein a set of electric wires is provided for each terminal of the transformer, and the set of electric wires is attached to both sides of the terminal. (3) A plurality of transformers arranged oriented in a predetermined direction, a pair of gun arms that can be opened and closed with each other, a holder that attaches an electrode to each gun arm and that can be detached from each other, a terminal of each transformer, and the above-mentioned. 1. A welding gun with a transformer, comprising a plurality of electric wires electrically connected to an electrode and having the same length for each gun arm.